mnmontana

Ok, pulling my hair out now... I Have had this truck for a week now and its driving me insane.

Engine is misfiring, not constant though. Specifically hitting bumps will trigger it to work right / not work. So I am assuming there is a loose connection somewhere.

When it works, it works great, nice and quick, good pickup, etc. When its NOT working, it stutters, wont get out of its own way, and bogs out.

I replaced the plugs, wires, ignition coil. Cap & rotor look new. Same issue...

I replaced the fuel filter. All the vacuum lines have been replaced or verified to be good.

I went over the engine with throttle body cleaner while running looking for vacuum leaks, everything has been fixed, and hooked up properly according to my book.

Engine still has the misfire. I put the old coil back in, same issue, rechecked each and every spark plug wire, checked each plug for spark, tried pulling 1 plug at a time and it seems to get evenly worse with each plug. So Maybe timing?

Anyone have any ideas???

mnmontana

woops, forgot to mention... 1986 Toyota 4runner, 2.4l EFI DLX model

I tried pulling each spark plug wire one at a time. Problem doesnt seem to be with a specific cylinder. So I am guessing timing now.

mnmontana

Just bought a vacuum pressure guage, compression guage, timing gun, and a tach. set the idle speed & timing right, still has the issue.

Found that the vsv wasnt letting any vacuum through, I bypassed it, engine reved up a bit, and sounded great. checked the timing again, it seemed right... truck sounds perfect now...

Take it for a ride arround the block... same freakin issue, only now it seems to do it anytime the gas is hit, regardless of bumps.

when gas is floored, it chugs for like 10 seconds, then takes off like a bat out of hell, and moves 'nicely'.

annoyingrob

I would check your fuel system. I had a very similar problem, which was happening because two of the injectors were stuck open, flooding those cylinders with too much fuel.

Check your FPR, specifically the vacuum line to it. run some injector cleaner through the system too. It would also be a good idea to look at your TPS. Make sure it's properly adjusted, and that the connector is in good shape.

mnmontana

Thanks, I will check them tonight after work. Also, I found some more info for this puzzle.


Under near the air intake, there was a danglingwire, there are 2 similiar conenctors there. 1 fits, the dangling one does not.

I searched and could not find where it plugs to. looks like a fuel injector connector, but the key on it wont let it fit on any injectors (or any connectors I could find) It has 2 wires on it, one is black & white, the other Black and yellow.


I also found that the prev. owner had spliced a wire from the first injector to the 4th injector. When I removed this wire, the engine sounded horrible, when putting it back on, it sounded good again at idle.

Still does the hesitation/stumble/hiccup/misfire thing under acceleration though.

mnmontana

FPS = fine, vacuum line works (checked with vacuum pressure guage), TPS = seems fine, connectors are ok, I tried adjusting a few times, still hasnt solved the issue. I suppose next is the FI cleaner.

mnmontana

After reading a few posts about the TPS, I decided to just replace it... after the new one was in, it ran GREAT, after about 10 minutes or so, same old stuff. So I suppose it was just a matter of coincidence.

Today we cleaned out the engine compartment thoroughly, moved arround a bunch of wires/hoses during cleaning. Started the truck to put it back in the garage, and it ran great, went arround the block a few times and it started again.



>>
I am now suspecting its a heat based issue, im letting the truck cool down right now to try it arround the block again to see if it does ok.

annoyingrob

I still think it's a fuel issue. A cold engine will run smoother under a super-rich condition than a warm one.

I don't like that jumper on the injector. I know the injectors are fired in pairs, off of two separate injector drivers, but I don't have my diagrams in front of me to tell you which pairs are connected. It's either 14, and 23, or it's 13, 24. If they are wired 13, 24, then that jumper points to a dead injector driver in the ECU. At any rate, something is up woth your injector wiring. I would trace it all to figure out what's happening.

If you can, take a lightbulb, and cinnect it to the injector plug, one at a time, and watch what it does when the engine is running (if you can keep it running on 3 cylinders), or at the very least, while cranking. If the light keeps on, or stays off, you have a problem.

abecedarian

With the 22RE, ALL 4 injectors are fired at the same time- and this applies to all years of the 22RE engine. Even though the wiring implicates separate firing events, you'll find that all 4 injectors are tied into the same ground and signal points.

for more detailed info on the TPS: http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

abecedarian

misfiring based on engine temperatures implies issues with the coolant temp sensor and the AFM... not always true, but could

mnmontana

Hey all, thanks for the interest. It appears heat/cold has nothing to do with the issue, acts the same weter its hot or cold.

I did hower find that 'pulling on a wire' makes the issue appear and dissapear. I figured 'Loose wire! thats it!' followed the wires, and I got to an injector where the metal clips slide in and out of the connector. Oddly enough, this is one of the injectors that the prev owner had spliced into. So I got a new connector, rewired it, and same issue... Sometimes it works great, sometimes it runs like crap...

There is a big bunch of wires all wrapped up, going to each fuel injector (including the cold start injector) and the igniter. The rest go into the body of the truck, which I assume goes to the ECU. Moving this bulk of wires is what triggers everything... So it looks like I am in for a loooooooong process of pulling apart each connector and checking for bad contacts.

In retrospect... I should have looked this truck over better before buying it. It ran like crap when I got it, but I figured 'Hey, I've rebuilt tons of chevy 305
s... I could easily fix this up!' I miss the good old days when gas was cheap and a big old gas guzzler was acceptable, slap on an edelbrock carb & intake, hookup 3 vacuum lines and be done.

mnmontana

Ok, the truck hates me..... it really does, I went out there with a video camera to record my wiggiling the wire to make it 'good and bad' to post on the forum here.... wouldn't do it.

I drove arround the block, nothing.... did a little rough driving (aiming for pot holes n such), works like a champ! So tommorow, I will try again and post the video if it acts up


On a side note, if anyone wants to see pics of my truck: http://images.strangeusa.com/uploads (You will notice the leopard print carpet... please note this was NOT my doing, lol.... and in fact, we replaced it with black carpetting on the 3rd day of owning it)

blaiwayw

Did you find where that connector goes? I just finished rebuilding my 86 4runner 22RE. I had two connectors I couldn't find a home for. One was rather dirty inside so it never was connected. The other was just like you describe. Mine went to the Auxillery Air Valve. It's the valve with small water hoses connected to it and adjusts air to the the intake plenum dependent on engine temp. Hard to see, as it connects to the rear of the valve. Wayne in Great Falls.

mnmontana

http://images.strangeusa.com/uploads/Actingup/ - Videos

http://images.strangeusa.com/uploads/engine/ - images

I recorded videos at the engine compartment, the tail pipe, and the driver seat. So everyone can hear the noise it makes. I know a true drive arround the block with sound would be more beneficial, but my wife won't let me leave the camera under the hood while driving, lol.

I recorded while it was acting up, sad part is... now it wont run right at all. I found that the #4 injector connector was broken (as every connector in the truck is apparently), I made sure the connector was on good, and rebent the metal clip to hold it in place.



In reply to blaiwayw, the AAV is connected, I am guessing the unknown connector is just a 'test plug' then, since it is dirty on the inside as well... it apparently hasnt been connected in a long time.

mnmontana

Images of the engine with the plenum & fuel rail removed

http://images.strangeusa.com/uploads/plenum

http://images.strangeusa.com/uploads/intake/

mnmontana

Update, just got the truck back together.... cleaned out all the nasty sludge in the intake and plenum, removed a section of air filter from the plenum, fixed a wrecked intake gasket, replaced a welded shut EGR pipe with a new junk yard Egr valve (tested and works properly). Re-verified all my vacuum lines, Replaced the TPS sensor, changed the oil & filter, drained the radiator & flushed, replaced all gaskets in my journey into the engine... Replaced the cold start injector.

And it still hesitates!!! Only difference now, is it sounds different, and has a little more power.

just a 22re

what about letting it run and shake the ecu and wires?

ecu is on the pass side kick panel

mnmontana

Update, replaced all 4 fuel injectors with brand new ones, still hesitates.

Did a compression check, and they are all fine (120 +/- 5psi) on all 4, so its a tiny bit low, but even.

Something VERY odd found, when unplugging all the sparks (1 at a time), when #4 is disconnected, the engine revs UP about 200 rom, it seems to run a little smoother too. My headers dont look stock, and the o2 sensor is only on cyl 3 & 4.

I guess its time to bring it to the dealership and pay 95 bucks for a diagnostic

randy59840

runs good until it warms up then it starts running like crap, especially @ a lower rpm or like driving through town it will miss all the way until you pick up speed then it runs like a top. any pointers? thanks, randy

bipolarandproud

I would probably be looking for a vacuum leak Randy .